A Snake River sockeye salmon, Oncorhynchus nerka, at Eagle Fish Hatchery in Eagle, ID. This is a 2019 hatch year fish, so when photographed in 2021 it was still a smolt, and not quite an adult.
This species was nearly lost to extinction, getting as low as 16 founder fish for the breeding program. Today, hundreds are produced in a hatchery setting, but the fish are still having difficulty making it in the wild, with overfishing, pollution and a series of dams restricting their movement to their spawning grounds near Redfish Lake, ID. This fish has the longest run inland and spawns at the highest altitude, of any sockeye salmon on Earth.